By Nauman Zafar | Party Wall Consultant | Survey of Party Wall · Last Updated: May 2026

Content reviewed against RICS professional standards and Pyramus & Thisbe Club best practice guidelines.

Party Wall Notice Explained: What It Is, Which Type You Need, and How to Serve It Correctly in London

Most London homeowners hear about party wall notices in week eight of their project when the builder is booked and the start date is set. Here is the problem: the minimum notice period for work to an existing party wall is two months. If you have not served notice yet, your builder is sitting on a live project with nowhere to go. The party wall notice is not a formality you fit around the build programme. It is a legal prerequisite that controls when the programme can start.

This guide explains exactly what a party wall notice is, which of the three types applies to your project, what every valid notice must contain, how to serve it correctly, what happens when your neighbour responds (or does not), and the six mistakes that invalidate a notice and restart the clock. Read this before you book the builder, not after. For the full statutory framework behind notices, see our complete guide to the Party Wall Act 1996.

What Is a Party Wall Notice

A party wall notice is a formal written document served by a building owner on every adjoining owner before starting notifiable building work under the Party Wall etc. Act 1996. It does three things. It tells the adjoining owner exactly what you plan to do and when. It starts a statutory clock that determines the earliest date work can begin. It formally engages the Act’s framework of rights and protections for both sides.

The notice is not a courtesy letter. It is a statutory instrument. Serving the wrong type, addressing it to the wrong person, or missing a mandatory piece of information makes the notice legally deficient. A deficient notice does not start the statutory clock. You lose the time you thought you had bought, and every day of delay on a London building site costs money.

Who must serve it

The building owner — the person or company carrying out the works — is responsible for serving the notice. This applies equally to homeowners, developers, landlords, and long leaseholders. If you are the one doing the work, the obligation to serve sits with you. Your architect, structural engineer, or party wall surveyor can draft and serve notices on your behalf, but the legal responsibility remains yours.

Who must receive it

Every adjoining owner must receive a notice. Under Section 20 of the Act, adjoining owner means every person with a freehold interest or a leasehold interest for a term greater than one year in a property that is affected by the proposed works. In a converted Victorian house with three long-lease flats, the building owner may need to serve separate notices on three leaseholders and one freeholder — four notices for one building. Always check HM Land Registry before serving. Serving on the occupier instead of the owner is one of the most common errors and makes the notice invalid.

The Three Types of Party Wall Notice

The Act provides three distinct notice types. Each covers a different category of work, carries a different statutory period, and requires different supporting documentation. One project often triggers more than one type simultaneously.

Notice type 1 — Line of Junction Notice (Section 1)

This notice applies when you want to build a new wall on or astride the boundary line between your property and your neighbour’s. Common triggers: the flank wall of a side return extension, a new garden wall on the boundary, or a new external wall built right up to but not crossing the boundary line.

Notice period: one month minimum before the intended start date. The adjoining owner has 14 days to respond. If they consent, you can build the wall astride the boundary as a shared party wall. If they do not consent within 14 days, you may only build wholly on your own land. The notice must describe the intended wall, state the proposed start date, and be accompanied by plans where relevant.

Notice type 2 — Party Structure Notice (Section 2)

This is the most commonly served notice in London. It governs any work to an existing party wall or party structure under Section 2 of the Act. Works covered include cutting in steel beams, raising the height of a party wall, underpinning a shared wall, removing a chimney breast attached to the party wall, inserting a damp proof course, exposing a party wall by removing a lean-to, and demolishing and rebuilding a party wall. The notice is served under Section 3 of the Act — but the works it covers are those defined in Section 2. This distinction matters because several competitors incorrectly label this a “Section 3 Notice.” The correct term is Party Structure Notice; it governs Section 2 works and is served under Section 3.

Notice period: two months minimum before the intended start date. This is the longest notice period in the Act. If your loft conversion requires steel beams into the party wall and you have not served notice, you need two clear months before your builder can touch that wall. The notice must name the building owner, name the adjoining owner, identify the property, describe the works in specific terms, and state the intended start date.

Notice type 3 — Notice of Adjacent Excavation (Section 6)

This notice applies when your excavation sits within 3 metres of a neighbouring building and goes deeper than their foundations (Section 6(1)), or within 6 metres where your dig intersects the 45-degree plane from the base of their foundations (Section 6(2)). In London, where Victorian terraces sit on 450 to 900 millimetre footings and modern Building Regulations demand 1,000 to 1,500 millimetre foundations, this notice fires on almost every rear extension, side return, and basement in the capital. For a full breakdown of the 3-metre and 6-metre rules, see our Section 6 excavation rules guide.

Notice period: one month minimum. The notice must include plans and sections showing the proposed excavation depth and its position relative to neighbouring structures. This is a mandatory statutory enclosure — a Section 6 notice without drawings is deficient and invalid.

Three Notice Types at a Glance

Notice type	Act section (works)	Served under	Period	Drawings required	Common London trigger
Line of Junction Notice	Section 1	Section 1(2) or 1(5)	1 month	Recommended, not mandatory	Side return flank wall, new boundary wall
Party Structure Notice	Section 2 (works)	Section 3	2 months	Recommended	Loft steel beams, chimney removal, underpinning
Notice of Adjacent Excavation	Section 6	Section 6(5)	1 month	Mandatory	Rear extension, side return, basement excavation

What Every Valid Party Wall Notice Must Contain

The Act does not prescribe a standard form for any notice. But it does prescribe the minimum content. A notice missing any of these elements is legally deficient and does not start the statutory clock.

Mandatory content for all three notice types

Every party wall notice must include: the full name and address of the building owner; the full name and address of every adjoining owner being served; the address of the property where works will take place (this may differ from the building owner’s home address); a clear description of the proposed works including the type of work, the intended location, and any relevant structural method; the proposed start date (this must be at least one or two months from the date of service depending on the notice type); and an explicit statement that the notice is served under the Party Wall etc. Act 1996.

Additional mandatory content for Section 6 notices

A Notice of Adjacent Excavation must additionally include plans and sections showing the site of the proposed excavation and its depth, together with the position of any new building or structure to be erected. It must also state whether the building owner proposes to underpin or otherwise strengthen or safeguard the neighbouring foundations. These are not optional. A Section 6 notice without drawings is invalid regardless of how well-worded the rest of it is.

The notice validity period

Once served, a valid party wall notice remains valid for twelve months. If the notifiable works have not started within twelve months of service, the notice lapses and must be re-served. Do not serve notice too early. There is no benefit to serving eighteen months ahead and significant risk that the notice lapses before the project reaches site.

How to Serve a Party Wall Notice Correctly

Getting the content right is only half the job. Service must also be carried out in a way the Act recognises. A perfectly drafted notice served incorrectly is still an invalid notice.

Four valid service methods

Section 15 of the Act specifies the permitted service methods. Hand delivery to the adjoining owner in person, or through the letter box of the property. First class post addressed to the adjoining owner at the property. Registered or recorded post with proof of delivery. Electronic service, but only where the recipient has previously given written consent to receive notices electronically and has provided a specific electronic address for that purpose. Email without prior written agreement is not valid service. This catches a significant number of building owners who assume email is acceptable.

Keep proof of service

The date of service starts the statutory clock. If a dispute later arises about whether notice was validly served, or on what date, you need documentary evidence. For hand delivery, use a witness and make a written note. For post, keep the tracked delivery receipt. For electronic service, keep the written consent agreement and the delivery confirmation. A party wall surveyor serving notices on your behalf will maintain a formal service record as a matter of course.

The 14-Day Response Window and What Happens Next

Once a valid notice is served, the adjoining owner has 14 calendar days to respond in writing. Three outcomes are possible and each one leads somewhere different.

Outcome 1 — Written consent

The adjoining owner signs and returns the acknowledgement within 14 days confirming they consent to the works. The statutory process ends here for that relationship. The works can proceed on the notified start date. The building owner is still bound by the Act’s duties of care, compensation obligations, and the right to make good any damage. Consent is not a waiver of those obligations — it just removes the need for a surveyor-produced award. Keep the written consent document with your project file.

Outcome 2 — Written dissent

The adjoining owner formally objects within 14 days. A dispute exists. Both parties must appoint surveyors. The building owner appoints their own surveyor. The adjoining owner appoints theirs. Alternatively, both agree on a single agreed surveyor. The surveyor or surveyors produce a party wall award before works start. The building owner pays the reasonable costs of the award process including the adjoining owner’s surveyor fees.

Outcome 3 — No response (deemed dissent)

The adjoining owner says nothing for 14 days. The Act treats silence as dissent under Sections 5 and 6(7). A dispute is deemed to have arisen. The surveyor appointment process begins exactly as if the neighbour had formally objected. The building owner then serves a formal request giving the adjoining owner 10 days to appoint a surveyor. If they still do not appoint, Section 10(4) of the Act allows the building owner to appoint a surveyor on the adjoining owner’s behalf. The process continues and produces a binding award regardless of the neighbour’s continued silence.

The Deemed Dissent Timeline — Day by Day

Day	Event	Action required
Day 0	Notice served on adjoining owner	Keep proof of service with date
Day 1-14	Response window — consent or dissent	Wait. Chase informally if no reply by day 10.
Day 14	If no written consent — deemed dissent fires	Serve 10-day surveyor appointment request immediately
Day 15-24	Neighbour must appoint surveyor within 10 days	If no appointment by day 24, appoint on their behalf under Section 10(4)
Week 4-10	Surveyors produce award	Provide method statement, drawings, schedule of condition access
Award served	Works can begin	Follow award conditions exactly. Document with site diary and photos.

Six Mistakes That Invalidate a Party Wall Notice

These are the six errors that restart the clock most often on London building projects. Each one is avoidable.

Mistake 1 — Wrong recipient

Serving the notice on the occupying tenant instead of the registered freeholder or long leaseholder. Always check HM Land Registry before serving. A £3 title register search prevents a two-month delay.

Mistake 2 — Missing drawings on a Section 6 notice

A Notice of Adjacent Excavation without plans and sections showing depth and position is invalid by statute. The drawings are mandatory. A verbal description of the foundation depth is not sufficient.

Mistake 3 — Vague start date

Stating “summer 2026” or “as soon as possible” as the intended start date. The start date must be a specific date at least one or two months from service. A vague date renders the notice deficient.

Mistake 4 — Email service without prior written agreement

Email is only valid where the adjoining owner has previously given written consent to receive notices electronically and provided a specific electronic address. Sending a notice to a general email address without that prior agreement is not valid service under Section 15 of the Act.

Mistake 5 — Missing joint owners

A property owned jointly by two registered proprietors requires the notice to name both. A notice naming only one joint owner is served on the wrong party and is deficient. In a flat block with four owners, you need four notices.

Mistake 6 — Wrong notice type for the works

Serving a Section 6 Notice of Adjacent Excavation when the works actually require a Party Structure Notice for steel beams into a shared wall — or vice versa. Each notice type covers specific categories of work. Using the wrong type means the correct works are never properly notified.

Counter Notices — What Your Neighbour Can Demand

Under Section 4 of the Act, an adjoining owner who receives a Party Structure Notice can serve a counter notice within one month of receipt. A counter notice can request additional works for the adjoining owner’s own benefit — for example, chimney flues being incorporated into the new structure, or deeper foundations to allow future development. The building owner must comply with the counter notice if it is reasonable. The adjoining owner bears the cost of any additional works they request for their own benefit. Counter notices are relatively rare in residential projects but are common on mixed-use and commercial party wall matters.

Notice Costs — What You Will Pay

Route	London cost 2026	Best for
DIY using GOV.UK template	Free (postage only)	Simple Section 1 notice, consenting neighbour, no excavation
Surveyor-drafted notice only	£200 to £400	Section 2 or 6 notice where drawings are complex
Notice plus schedule of condition	£650 to £1,100	Neighbour likely to consent but wants condition record
Full award (agreed surveyor)	£900 to £1,800	Neighbour dissents or does not respond
Full award (two surveyors)	£1,800 to £3,500	Neighbour appoints own surveyor

For a full breakdown of costs by project type, see our party wall surveyor fees guide.

Case Law That Governs Notice Validity

Power and Kyson v Shah [2023] EWCA Civ 239

The “no notice, no Act” principle. Without a valid notice the Act is not engaged. The adjoining owner has no recourse to Section 10 dispute resolution and is left with common law remedies only. The building owner simultaneously loses the Act’s protective framework. Both sides suffer. This is the single most important judgment for anyone considering whether to bother with the notice process.

Nutt v Podger and Veda Road Ltd [2021]

Verbal consent from a neighbouring occupier was treated as legally worthless. The court confirmed that consent under the Act must come from the person with the relevant legal interest in writing. A handshake agreement with the person who lives next door is not consent under the Act.

Ormiston-Kilsby v Fattahi [2019]

A mandatory injunction was granted requiring partial demolition of an extension built without party wall notices. The court ordered structural removal, not just a financial penalty. Ignoring the notice obligation is not a low-risk gamble.

Onigbanjo v Pearson [2008] BLR 507

Written consent given by an adjoining owner after receiving a valid notice does not strip away the right to invoke surveyor jurisdiction if a specific dispute arises during works. Consent is not an all-encompassing waiver.

Key Takeaways

• Three notice types: Line of Junction (Section 1, one month), Party Structure (Section 2 works, two months), Adjacent Excavation (Section 6, one month). Know which applies before you book a builder.
• A Section 6 notice without drawings is invalid by statute. No exceptions.
• Email service is only valid with prior written consent from the recipient. Posting to the property is always the safe default.
• Silence from your neighbour for 14 days triggers deemed dissent. It is not a green light — it starts the surveyor appointment process.
• Following Power and Kyson v Shah, skipping the notice strips both sides of the Act’s protection simultaneously.
• Serve at least three months before your intended start date to absorb the notice period and any award timeline without disrupting your build programme.

Frequently Asked Questions: Party Wall Notice

How long before work starts do I need to serve a party wall notice?

One month for a Line of Junction Notice (Section 1) or a Notice of Adjacent Excavation (Section 6). Two months for a Party Structure Notice covering Section 2 works such as steel beams or underpinning. Always serve at least three months ahead of your intended start date to absorb both the notice period and any award timeline.

Can I serve a party wall notice by email?

Only if the adjoining owner has previously given written consent to receive notices electronically and provided a specific electronic address under Section 15 of the Act. Without that prior written agreement, email service is invalid and does not start the statutory clock.

Does my neighbour have to agree to my party wall notice?

No. The Act does not give a neighbour a veto over lawful building work. If they dissent or do not respond within 14 days, the surveyor award process begins and work proceeds once the award is in place. Only a court can stop lawful work, and only where the Act has not been followed correctly.

What happens if I start work without serving a party wall notice?

Following Power and Kyson v Shah [2023], without a valid notice the Act is not engaged. Your neighbour can seek a court injunction to stop work. They can pursue common law claims for nuisance, trespass, and negligence with no statutory cap on damages. Courts have also ordered demolition of completed works in cases of serious breach.

Can I serve a party wall notice before I have planning permission?

Yes. The Party Wall Act is entirely separate from planning permission and Building Regulations. You can serve notice before planning is granted. If planning is refused, the notice lapses without consequence. Serving early protects your build programme.

Do I need a party wall notice for internal work?

Not for purely cosmetic internal work. Plastering, rewiring, and painting do not trigger the Act. But any structural work that cuts into, undermines, or alters a party wall — including removing a chimney breast, inserting a steel beam, or exposing a party wall by removing a lean-to — requires a Party Structure Notice under Section 2.

How long is a party wall notice valid for?

Twelve months from the date of service. If the notifiable works have not commenced within twelve months, the notice lapses and must be re-served with a fresh notice period running from the new service date.

Related Guides

• Complete Guide to the Party Wall Act 1996
• Section 6 Excavation Rules: 3m and 6m Explained
• Neighbour Ignoring Your Party Wall Notice
• DIY Party Wall Notice or Surveyor?
• Single Storey Extension Party Wall Guide